1. Field of the Invention
The present invention relates to a nickel-metal hydride secondary battery module including a plurality of compartments each accommodating a power generating element, the compartments being communicated with one another, and a secondary battery module manufacturing method.
2. Description of Related Art
Some secondary batteries are each provided with a safety valve in a battery case formed with compartments each of which accommodates a power generating element. This safety valve will be opened when gas is generated from the power generating element and the inner pressure of the compartment increases abnormally, so that the gas is safely released to prevent deformation or breakage of the compartment.
In the case of a secondary battery designed such that the battery case has a plurality of compartments each of which accommodates a power generating element, it is preferable to provide a safety valve for each compartment. However, such configuration needs many safety valves. Accordingly, as disclosed in JP2004-319096A, there has been proposed a nickel-metal hydride secondary battery (a nickel-metal hydride secondary battery module) provided with partition walls separating battery chambers (compartments) are formed with communication holes through which the compartments are communicated with one another and a single safety valve is provided in a battery case.
In this nickel-metal hydride secondary battery module disclosed in JP2004-319096A, the gas generated from any of the power generating elements could be released safely through the communication holes and the safety valve.